The present invention relates to a sound signal adding apparatus for reproducing sound from a sound data. More particularly this invention relates to a sound signal adding apparatus in which there is a limitation on the number of reproducible sound generators as well as to a method of reproduction sound.
Description is made hereinafter for a sound signal adding apparatus based on the conventional technology. FIG. 3 is a view showing a configuration of the sound signal adding apparatus based on the conventional technology. As shown in FIG. 3, designated at the reference numeral 1 is a sound data storing section comprising a semiconductor storage device such as a ROM for storing therein a plurality of sound data (1) to (M). Designated at 5 is a sound data selector for selecting the sound data under a microcomputer control. Designated at 2 is a data demodulating section (which comprises a first data demodulating section 2a, a second data demodulating section 2b, and a third data demodulating section 2c) for receiving the plurality of sound data from the sound data storing section 1 and demodulating each of the sound data for reproduction. Designated at 4 is a data adding section for receiving the demodulated data outputted from the data demodulating section 2 and adding each of the signals to output the added signal. The maximum number of reproducible sound generators is different depending upon the type of the device. However, for convenience in description, it is assumed herein that the maximum number of sound generators is three in this example based on the conventional technology. In other words, the maximum selectable number of sound generators in the sound data selector 5 is three.
The conventional type of sound signal adding apparatus configured as described above controls the sound data selector 5 during sound reproduction in such a way that the number of sound generators does not exceed the maximum reproducible number of sound generators at any time. Therefore, when a number of sound generators in current reproduction is three, and if an additional sound generator different from the sound generators which are being currently reproduced is to be reproduced, for example, any one of the sound generators which are being currently reproduced is stopped and the newly added sound generator is reproduced.
Furthermore, when a so called chain reproduction is to be performed in which a particular rhythm pattern to be reproduced using a plurality of sound generators is linked to a rhythm pattern different therefrom, then in the conventional type of sound signal adding apparatus the latter rhythm pattern is reproduced after the former rhythm pattern is completely finished.
In the conventional type of sound signal adding apparatus, however, when a number of sound generators which are being currently reproduced is three and when an additional sound generator different from these sound generators is to be reproduced then a non-linear noise due to interruption of the sound signals may occur which causes quality of sound to be degraded.
In addition, when the chain reproduction is to be performed in the conventional type of sound signal adding apparatus, reproduction of a rhythm pattern is restricted due to the maximum number of reproducible sound sources. In other words, a next rhythm pattern can not be reproduced until the rhythm pattern in current reproduction is finished, so that even if a user wants to immediately reproduce a next rhythm pattern, for example, if reproduction of any one of the sound generators which have been linked for the rhythm pattern in execution is not finished, the next rhythm pattern can not be reproduced until the rhythm pattern is completely finished.
It is an object of the present invention to obtain, for the purpose of solving the problems described above, a sound signal adding apparatus which can prevent occurrence of nonlinear noise due to interruption of sound signals and can immediately reproduce, for chain reproduction, the next rhythm pattern without waiting for a rhythm pattern in current reproduction to be finished, as well as to obtain a method of reproduction of sound.
In the present invention, a sound data searching unit identifies a sound signal having the least remaining reproduction time, and an output level control unit mutes this signal. Therefore, occurrence of non-linear noise due to interruption of sound signals can be suppressed and hence quality of sound can largely be improved.
In the present invention, the sound data searching unit and the output level control unit are utilized even when the chain reproduction is performed. Therefore, a next rhythm pattern can immediately be reproduced before reproduction of all the sound generators for a rhythm pattern in execution is finished, so that it is possible to solve the problem in the conventional technology that a next rhythm pattern can not be reproduced until a rhythm pattern in execution is completely finished.
In the present invention, a. sound signal having a least reproduction remaining time is identified in the sound data searching step, and this sound signal is muted in an output level control step. Therefore, occurrence of non-linear noise due to interruption of sound signals can be suppressed and hence quality of sound can largely be improved.
In the present invention, the sound data searching step and the output level control step are utilized even when the chain reproduction is performed. Therefore, a next rhythm pattern can immediately be reproduced before reproduction of all the sound sources for a rhythm pattern in execution is finished, so that it is possible to solve the problem in the conventional technology that a next rhythm pattern can not be reproduced until a rhythm pattern in execution is completely finished.